Butterfly conveyor clip for flat bed filter

ABSTRACT

A filter of the type having a movable perforate conveyor formed of a series of transverse bars and interconnecting links includes a filter medium supported on the top surface of the conveyor for movement therewith in a housing which cooperates with the conveyor and filter medium to form a pool of liquid to be filtered on the filter medium. Fixed sealing strips are located on opposite sides of the pool and bear against side edge portions of the filter medium to inhibit flow of liquid from the sides of the pool and means operatively connected to the perforate conveyor support the portions of the filter medium passing under the sealing strips. This supporting means comprises a series of clips, each of which has an upper surface substantially coplanar with the top surface of the conveyor and downwardly extending tab means for removably securing the clips to the conveyor.

United States Patent [191 Kaess BUTTERFLY CONVEYOR CLIP FOR FLAT BEDFILTER [75] Inventor: Frank R. Kaess, Oneida N.Y. [73] Assignee:Clarkson Industries, 1nc., New

York, N.Y. I

[22] Filed: Aug. 1, 1973 [21] Appl. No.: 384,424

[52] US. Cl. 210/387; 198/195; 210/401 [51] Int. Cl. B0ld 33/32 [58]Field of Search 198/189, 194, 193, 195,

[561 References Cited UNITED STATES PATENTS 2,621,779 12/1952 Harter198/194 3,045,809 7/1962 Bechtel, Jr. 198/195 3,087,620 4/1963 Hirs 1210/387 X 3,333,705 8/1967 Lee 210/251 3,468,424 9/1969 Laugel 210/4013,477,583 11/1969 Krynski et a1.... 210/401 3,483,978 12/1969 Krucklauer210/232 X 3.706200 12/1972 Mueller 198/189 X Apr. 8, 1975 [57] ABSTRACTA filter of the type having a movable perforate conveyor formed of aseries of transverse bars and interconnecting links includes a filtermedium supported on the top surface of the conveyor for movementtherewith in a housing which cooperates with the conveyor and filtermedium to form a pool of liquid to be filtered on the filter medium.Fixed sealing strips are located on opposite sides of the pool and bearagainst side edge portions of the filter medium to inhibit flow ofliquid from the sides of the pool and means operatively connected to theperforate conveyor support the portions of the filter medium passingunder the sealing strips. This supporting means comprises a series ofclips, each of which has an upper surface substantially coplanar withthe top surface of the conveyor and downwardly extending tab means forremovably securing the clips to the conveyor.

18 Claims, 7 Drawing Figures 68 326 I5 122 I28 32d SET 1 OF 3PATENTEBAPR 81975 l l d PATEMEDA WQWQW n w w/ 3 n E 2 Q: I\A E W u u W iw x u u n flr w a m.] E7? wT 4\ A, 07 n i E, "3;; n m; 7/ U M BUTTERFLYCONVEYOR CLIP FOR FLAT BED FILTER This invention relates generally tofilter devices and more particularly to clip members that areresiliently attachable to and detachable from a perforate conveyor foruse in connection with the side sealing means of flat bed filters suchas that shown in US. Pat. No. 3,333,705 issued to W. J. Lee.

Flat bed filters commonly comprise an endless conveyor, the upper reachof which carries a strip of filter medium such as paper or cloth. Theconveyor and filter medium cooperate with the sides of the filter tankto define a trough adapted to contain a pool of the liquid to befiltered. The conveyor is periodically advanced to carry fresh filtermedium into one end of the pool and remove filter medium carrying alayer of the filtered solids from the other end of the pool.

In order to minimize leakage of unfiltered liquid in such filters,sealing means are provided on each side of the pool. One conventionaltype of seal is that shown in the Lee Patent, US. Pat. No. 3,333,705referred to above, the disclosure of which is incorporated herein byreference. In that type of seal, the side edge portions of the conveyorhave strips of impervious material, e.g., rubber, attached to the uppersurface of the conveyor, with the side edges of the filter mediumextending thereover. A flexible resilient sealing member is cantilevermounted on each side wall of the tank above the conveyor and has asealing rib that bears downwardly against the portion of the strip offilter medium that overlies the strip of rubber at the edge of theconveyor. The sealing ribs thus cooperate with the rubber strips tominimize the leakage or seepage of unfiltered liquid at the sides of thepool.

While such seals have been found to be generally satisfactory, after thefilter has been in service for a time there is a tendency for the rubberstrip to become detached from the conveyor particularly at those pointswhere the conveyor passes over the sprockets on which it is supportedsince at those points the conveyor changes its direction of movementrather abruptly and creates stresses in the bond between the conveyorand rubber strip which tend to rupture the adhesion therebetween.

Accordingly, it is an object of the invention to provide an improvedmeans of sealing the side edges of the filter medium of a flat bedfilter. It is another object of the invention to provide sealing stripsat the side edges of such a conveyor that support the filter medium andmechanically engage the conveyor to minimize the possibility of thestrips becoming detached from the conveyor. It is still another objectof the invention to provide side sealing strips for such a conveyorwhich comprises a series of interpenetrating metal clips that areresiliently attachable to and detachable from the upper surface of theconveyor. It is also an object of the invention to provide a clip orclips that are resiliently engageable with and detachable from aperforate conveyor comprising links interconnected by transverse bars,and that are adapted to block off predetermined areas of the conveyor.

It is noted that although the present invention is described herein inconnection primarily with a filter of the type shown in U.S. Pat. No.3,333,705, as the description proceeds it will become apparent that theconveyor clips of the present invention are generally applicable forblocking predetermined areas of conveyors of general utility which havetransverse bars interconnected by links.

The above and other objects, features and advantages of the inventioncan best be understood and appreciated by reference to the followingdetailed description of the invention and to the accompanying drawingswhich illustrate a preferred embodiment thereof, wherein:

FIG. 1 is a semi-diagrammatic side elevational view of a flat bedfilter, constructed in accordance with the present invention and shownin section to illustrate the arrangement of the endless conveyor arounda sump tank and the relationship of the filter medium to the conveyor;

FIG. 2 is a partial vertical section, taken along line 2-2 of FIG. 1,showing the general relationship between the edge of the conveyor, theclips, the filter me dium and the cantilever mounted sealing rib;

FIG. 3 is a top plan view, taken along line 3-3 of FIG. 2, of an edgeportion of the conveyor showing a group of clips affixed thereto;

FIG. 4 is a fragmentary section taken on the line 44 of FIG. 3 showingin part the manner in which the clips are attached to the conveyor;

FIG. 5 is a fragmentary section taken on the line 55 of FIG. 3 andfurther showing the mode of attachment of the clips,

FIG. 6 is a fragmentary bottom plan view of the conveyor, furthershowing the relationship of the clips to the conveyor; and

FIG. 7 is a bottom perspective view of one of the clips.

Referring now to the drawing in detail, and initially to FIG. 1 thereof,it will be seen that a flatbed filter 10 incorporating the presentinvention, and constructed in a manner similar to that of the flat bedfilter shown in the above-mentioned Lee patent, includes a frame 12having side walls 14 (only one of which is seen in FIGS. 1 and 2)connected by a plurality of transversely extending plates which arewelded together to form a sump tank 16. These plates include a bottomwall member 18 and a pair of inclined end walls 20, 22 which are weldedtogether at their points of juncture 24 to form a waterproof containerwith the side walls I4.

The top of sump tank I6 is covered by a supporting bed 26 through whichliquid can drain into the sump tank. The supporting bed, as described inthe Lee patent, generally comprises a plurality of inverted channels(not shown) arranged in spaced relation, with each channel having a pairof depending side flanges on which rollers 28 are mounted at spacedpoints along the filter to support a conveyor belt 30 laterally andlongitudinally on the bed.

Conveyor 30 is an endless closed loop conveyor mounted on the frame in apredetermined position so as to move about sump tank I6. The conveyorhas atop run of flight 320 which extends between sprockets 34, 36 andrides on the downwardly curved supporting bed 26. A section 32!; of theconveyor 30 extends downwardly from sprocket 34 adjacent the end wall 20of the sump l6 and around a sprocket 37 at the lower left hand end ofthe tank. From sprocket 37 the conveyor 30 has a horizontal returnsection 32c under tank 16 which then turns around sprocket 38, and anend section 32d extending upwardly between sprockets 38 and 36 adjacentthe end wall 22 of the sump tank.

As seen most clearly in FIGS. 3 and 6, conveyor is formed from aplurality of generally zig-zag shaped transversely extending links whichare intercon nected in a generally overlapped or intermeshingrelationship by transversely extending pivot bars 42. The zig-zag links40 are formed or bent in a series of oppo sitely extending generallyU-shaped link sections each of which has bight portions 44 and legportions 46 extending therefrom. The transverse bars 42 pivotallyinterconnect the links through the legs 46 at locations adjacent bightportions 44, with the bight portions of the links received between thespaced bight portions in an adjacent link. In this manner the links areslightly over lapped with one another, but form a relatively flat andcontinuous top surface on the conveyor belt.

The connected links and transverse bars thus provide a chain typeconveyor. the edges of which are adapted to ride over and be engagedwith the sprockets 34-38. The transverse bars 42 give the conveyorsubstantial transverse strength; however, the edges 48 of the conveyorare supported. at least along the top run 320 thereof. by a dam plate 52(more fully described hereinafter) which is supported on an inwardlyextending ledge 54 secured to the side walls 14 of the filter frame. Itis noted that only one dam plate and one side edge 48 of the conveyorare shown in FIG. 2; however, the opposite side edge and supportconstruction is identical thereto.

The various drive and support sprockets 3438 for conveyor 30 consist ofa plurality of individual sprockets (e.g., between four and sixteen)mounted on common shafts extending between opposite sides of the fil terframe, with the sprockets 34 providing the drive power to the conveyor.Thus, the sprockets 34 are each mounted on a common shaft 56 which isdriven by a motor 58 through a conventional chain and sprocket drivetransmission 60. The use of a plurality of sprock ets extending acrossthe width of the conveyor supports the conveyor at each corner andprevents it from sagging in the middle of its width. As described in theLee patent, the drive to the conveyor is controlled by an adjustablevacuum switch which is subjected to the vacuum in the sump tank 16 andis connected to operate motor 58 to start and stop the conveyor atcertain low pressure differentials.

A liquid distributor 62 is located above the top surface of conveyor 30and directly above sump tank 16 for delivering the liquid to be filteredinto the filter unit. On the other hand, a discharge pipe 64, dependingfrom a box 66 projecting laterally through the side plate 14 of the sumptank provides a conduit for discharge of filtrate from the sump tank tothe location at which the filtrate is used; thereby to form a completedcircuit with distributor 62 for circulating the liquid filtrate from thefilter unit to the workpiece and then back to the filter unit.

A filter medium 68, in the form of a sheet of paper or cloth, isprovided or supplied in a roll 70 which is rotatably mounted at theright hand end of the machine. The filter sheet extends from the roll 70onto and in engagement with the conveyor 30 and is advanced there withby the motor 58. More particularly, as seen in FIG. 1, filter sheet 68extends along the curved top of the conveyor 30, in its path of travelover supporting bed 26, with the forward end of the filter medium andfilter cake thereon being discharged into a receptacle 72.

Sealing strips 74 (see FIG. 2) formed of a flexible material are securedto the side plates 14 of the filter frame with their inner edges 76overlying the side edges of the filter medium 68 to form a seal betweenthe side wall 14 and the filter medium. As a result, the downwardlycurved supporting bed 26 and the filter sheet 68 supported thereon byconveyor 30 forms a pool 78 of liquid to be filtered which can onlyescape by passing through the filter medium itself into the sump tank 22or by seepate through the side sealing strips 74.

In Operation, a vacuum pump 80, having an inlet 82 connected to sump l6and driven from motor 58 by a chain drive 84, draws air from sump I6 toreduce the pressure therein and cause the liquid to be filtered to beforced through the filter medium under atmospheric pressure, thereby tofilter the liquid and cause the same to enter the sump.

As thus far described, the fiat bed filter I0 is of substantially thesame construction as that of the filter described in theabove-identified Lee patent. As mentioned, in the filter disclosed inthat patent seepage through the sealing strips 74 is prevented by theprovision of an impervious rubber sealing strip secured to the conveyorsurface. This type of sealing arrangement creates several problems inthat the rubber seal tends to become disengaged from the conveyor chain,particularly where the chain moves about the sprockets. In accordancewith the present invention, an improved seal construction is providedwherein the sealing operation of the previously proposed rubber stripsis performed by independent clip members which are secured to theconveyor 30 adjacent the edges thereof so as to move below the sealingstrips 74. These clips are mechanically connected to the chain and forma substantially continuous support surface beneath the strip 74, therebyserving substantially the same function as the previously describedrubber strips, but overcoming the problems of the latter since the clipsremain at all times secured to the conveyor and are not subject toattack by the liquid to be filtered.

As seen most clearly in FIG. 3 of the drawing the conveyor 30 isprovided with a series of clips 90 (also referred to hereinafter asbutterfly clips) which have a configuration which is selected togenerally conform to the configuration of the zig-zag shaped links ofthe conveyor. Each clip is independently operatively connected betweenadjacent pairs of transverse conveyor bars 42 and substantiallycompletely covers the conveyor between successive links.

The construction of each clip 90 is identical and a typical clip isillustrated from below in FIG. 7 of the drawings wherein it is seen thatthe clip includes a main body portion 92 having a forward edge 94 and atrailing edge 96. The forward edge of the clip has a projection ortongue 98 extending therefrom, while the railing edge 96 has a recessI00 formed therein. As a result, the trailing edge 96 is provided with apair of projections or tongues 102 which extend oppositely of theprojection 98. The location and dimensions of the projections 98, 102are selected so as to be received within the general peripheralconfiguration of the U-shaped portions of the zigzag links, as seen inplan in FIG. 3. Thus, these projections give the clip its generallybutterfly configuration, with the central projection or tongue 98 at theleading edge of the clip received within one U-shaped portion of itsassociated zig-zag link 40 (i.e., the link whose perforations oropenings it covers) and the other two projections 102, being receivedwithin the adjacent two U-shaped portions of the link. In addition, thetongue 98 and recess 100 of the clip are generally complementary, sothat the tongue of one clip can fit into the recess of an adjacent clipwhen the clips are placed on the conveyor in a row, as seen in FIG. 3.In this manner a substantially continuous surface is provided along theperforate conveyor in order to support the filter sheet 68 beneath thecontinuous sealing strip 74. The main body portions 92 of the clipsthereby form a support surface for the sealing strips.

Clips 90 are secured to conveyor 30 by a plurality of tabs or extensions104 which extend downwardly from the projections 98, 102. These tabs 104have oppositely curved re-entrant surfaces 106, as seen in FIG. 7, so asto receive confronting surfaces of adjacent transverse conveyor bars 42.That is, as seen in FIGS. 4 and 5 of the drawing, the forward tab 104 ontongue 98 receives an adjacent bar 42 in its curved surface 106 while,on the other hand, the two tabs 104 along trailing edge 96 of clip 90(as seen in dotted lines in FIG. 4 and solid lines in FIG. 5) receivethe next conveyor bar 420 in their curved re-entrant surfaces 106a onthe side thereof which faces the preceeding conveyor bar 42. Thus, theclip is in effect wedged between successive conveyor bars by theresilient tab members 104, with the tab on the tongue or one clipengaging the same transverse bar as the tabs on the projections 102 ofan adjacent clip.

It is noted that clips 90 are preferably formed of a resilient metalmaterial such as stainless steel or the like; however, it iscontemplated that the clips may be formed of any other convenientresilient materials which would be suitable for use in a filterconveyor.

The resiliency of the material forming clips 90 holds the clips inengagement between the successive bars 42 and yet permits the clips tobe readily removed there from for replacement and readily insertedtherebetween. In this connection, it is noted that the free ends 108 ofthe tabs 104 are oppositely curved from the curvature of their adjacentre-entrant surface portions 106. In this manner, the extensions 108 actas cam members for the tabs when the clips are inserted between adjacentbars 42. That is, the first portions of the tabs which engage the bars42 upon insertion of the clips are the extensions 108. These extensionsthereby act to cam the tabs inwardly, i.e., towards the center of theclip, when a downward force is applied to the clip so as to guide thetabs 104 into position about bars 42. Once the tabs 108 have passed bars42, the tabs spring outwardly again against the bars to resilient holdthe clip on the conveyor.

It is noted that the particular shape of the clips 90 shown in FIGS. 3-7of the drawings is important where a conveyor having zig-zag links ofthe type illustrated in the drawings is utilized. The configuration isselected to substantially completely cover the adjacent portions of theconveyor, on which the clip is superimposed, but does not interfere withmovement of the conveyor, particularly about the sprockets. For example,if a clip having a square configuration were utilized, so that the bodyof the clips overlapped adjacent links, upon pivotal movement of anadjacent link with respect to the clip, as the conveyor goes about asprocket, the adjacent link would move against the clip and tend to re-'lease that clip from engagement with its associated conveyor bar. Thatis, considering FIG. 4 of the drawing, ifa square type clip wereutilized in lieu of the butterfly shaped clip of the present invention(i.e., if the clip did not have recess formed therein but had a straightrear edge 96) the clip would overlap the bight portion 44 of the nextlink in the conveyor (i.e., the bight portion immediately adjacent thetongue 98 of the next clip 90). In that case. when the link to which theclip 90 is connected begins to move about a sprocket, the link wouldpivot with respect to the succeeding link, causing the bight portion 44of the next link to engage the lower surface of the clip. Suchengagement of the bight portion 44 of the succeeding link with the clipwould cause the clip to become disengaged from the transverse bar 42.This is avoided by the construction of the present invention wherein thebutterfly shape is selected so as to keep the clip within the confinesof its own link and wherein the clip is dimensioned so that its widthbetween leading edge 94 and trailing edge 96 is less than the width ofthe zig-zag link. Accordingly, the clip does not overlap any portions ofany adjacent link, does not interfere with pivotal movement of theconveyor about the sprockets, and does not become disengaged from thesprockets because of the angular movement of the links with respect toone another as they pass about the curved path of travel or about asprocket.

Another feature of the invention is that the main body portion 92 ofclips 90 is bent slightly along angular lines adjacent the leading edge94 of the clip. That is, the shoulder portions or triangular sections I11 defined by lines 110 and leading edge 94 on opposite sides of tongue98 are bent slightly downwardly about the line 110, so that the edges112 of the clip bear firmly against the top surface of the conveyor 30.By bending the triangular portions 111 of the clip in this manner, theclip remains substantially coplanar or flush with the top surface of theconveyor so as to insure that the corners 114 thereof do notinadvertently extend above the top surface of the conveyor to interferewith the filter medium 68 or to otherwise interfere with the operationof the device.

As a result of the construction of clips 90, a substantially continuousband is formed on conveyor 30 where rib 76 of strip 74 engages thefilter medium. Accordingly, seepage or other migration of unfilteredliquid from the pool 78 through the sealing strips 74 is reduced to aminimum. Moreover, the resilient strip is supported on the conveyorsurface and cannot enter the perforations in the conveyor itself. Ofcourse, it will be understood that the construction at the opposite sideof the filter and conveyor 30 is identical with that described above andincludes sealing strip 74 and a series of clips 90 secured to theconveyor.

Filter 10 of the present invention also includes a pair of troughslocated at opposite edges of the conveyor 30, which troughs are ofsimilar construction to the troughs described in the above-mentioned Leepatent. Only one of the troughs is illustrated in FIG. 2 of the drawingsand it is to be understood that the trough at the opposite edge ofconveyor 30 is of identical construction. Essentially, trough 120 isformed from a horizontal wall (not shown) extending inwardly from theside wall 14 and a vertical wall 122 connecting the inner edge of thelower horizontal wall to the underside of the ledge 54. The latter hasopenings 124 formed therein so that any unfiltered liquid passingbeneath sealing strips 74 may move laterally along the top of the filtermedium around the side edge of conveyor 30 and drip onto the ledge 54.Such liquid will then flow through the openings 124 in the ledge, fallinto the trough 120 and be prevented from entering the tank 16. Asdescribed in the Lee patent, the trough supplies the unfiltered liquidflowing thereinto a sump 126 formed in sump l6 and separated from thefiltered liquid by a wall 128.

The flat bed filter described above operates in substantially the samemanner as the filter disclosed and described in the Lee patent discussedabove. Therefore, a detailed description of the operation of the de viceis not necessary herein. It will be appreciated, however, that the clips90 of the present invention, used in combination with the zigzag linkedconveyor serve substantially the same purpose as the rubber ribs of theLee filter in providing a support for the edge 76 of sealing strip 74below the filter medium. These clips are highly advantageous in thepresent invention since they are directly secured to the transverseconveyor bars and will not separate therefrom during movement of theconveyor into a curved path or around the respective sprockets.Moreover, neither the clips nor their connection to the conveyor aresubject to attack by the liquid to be filtered. Therefore, the clips andconveyors will have a relatively long and useful life. Further, in theevent that any one or more of the clips becomes worn or broken, thatclip can be readily removed and replaced by a new clip while theconveyor remains in the filter. Thus. the replacement of the clipsresults in no substantial down time for the filter since they eliminatethe necessity of completely removing the conveyor from the filter forrepair as would be the case with the Lee device. Accordingly, it is seenthat highly advantageous conveyor clips have been provided which are notonly relatively simply constructed and inexpensive but which alsoimprove the operation and operating life of flat bed filters.

Although an illustrative embodiment of the present invention has beendescribed herein with reference to the accompanying drawing, it is to beunderstood that the invention is not limited to that precise embodimentand that various changes and modifications may be effected therein byone skilled in the art without departing from the scope or spirit ofthis invention.

What is claimed is:

1. ln a filter of the type having a movable perforate conveyorcomprising a series of transverse bars and links interconnecting saidbars, a sheet of filter medium supported on the top surface of saidconveyor for movement therewith, means cooperating with said conveyorand filter medium for forming a pool of liquid to be filtered on saidfilter medium. and means comprising fixed sealing strips on oppositesides of said pool bearing against side edge portions of said filtermedium for inhibiting flow of liquid from the sides of said pool, theimprovement which comprises means operatively connected to saidperforate conveyor for providing a substantially continuous supportsurface for supporting the portions of said filter medium passing undersaid sealing strips, said supporting means comprising a series of clipseach of which has an upper surface substantially coplanar with the topsurface of said conveyor and re silient tab means for removably securingthe clip to the conveyor; said tab means comprising downwardly extendingcurved extensions of said clips resiliently engaging said transversebars of said conveyor; said clips having first and second opposite sideedges of predetermined generally complementary configuration includin gprojections having free end portions extending over their adjacenttransverse conveyor bars, thereby to form said substantially continuoussupport surface with adjacent clips; said tab means extending downwardlyfrom the free end portions of said projections to positions below andbeneath the projections for resilient engagement with their associatedtransverse conveyor bars.

2. A filter according to claim 1 wherein said clips each include atleast two downwardly extending curved extensions located in oppositesides of the clip for respective engagement with adjacent bars of saidconveyor.

3. A filter according to claim 2 wherein said downwardly extendingcurved extensions on said clips respectively engage confronting surfacesof adjacent bars of said conveyor.

4. A filter according to claim 3 wherein said clips are respectivelysecured to said conveyor between successive pairs of transverse conveyorbars in substantially longitudinal alignment with each other to form acontinuous row of clips along the conveyor.

5. A filter according to claim 4 wherein the curved extensions onadjacent sides of successive clips in said row of clips engage oppositesides of the same transverse conveyor bar.

6. A filter according to claim 1 wherein said projections on said clipscomprise a projecting tongue extending from one of said edges and a pairof spaced projecting tongues extending from the other of said edges anddefining a recess therebetween of generally complimentary configurationto the projecting tongue on said one of said edges; said clips beingsecured to said conveyor by said tab means with the tongue on said oneedge of each of said clips extending into the recess on the other edgeof its associated adjacent clip, thereby to form a substantiallycontinuous support surface.

'7. A filter according to claim 6 wherein each of said clips includes atleast three of said downwardly extending tab means formed thereon, oneof said tab means being formed integrally with and depending from thefree end of the tongue on said one edge of the clip and the other two ofsaid tab means being formed integrally with and depending from the freeends of the projecting tongues on the other edge of the clip adjacentsaid recess, said tab means respectively comprising resilient curvedextensions of the clips located below and be-- neath their associatedprojecting tongues for resiliently engaging the bars of said conveyor.

8. A filter as defined in claim 7 wherein said downwardly extending tabmeans are formed to resiliently engage confronting surfaces of adjacenttransverse conveyor bars.

9. A filter as defined in claim 8 wherein said tab means have re-entrantcurved surfaces formed thereon with the curved surfaces on the tabs atopposite side edges of said clips opening in opposite directions toengage the confronting surfaces of adjacent transverse conveyor bars.

10. A filter as defined in claim 8 wherein said tabs each have aninclined free edge portion defining a cam surface for guiding itsassociated tab into resilient mating engagement with its associatedtransverse conveyor bar.

11. A filter as defined in claim 7 wherein said tongue on said one edgeof each of said clips, and said one edge thereof, define shoulderportions in said clips adjacent said one edge thereof, said shoulderportions of said clips being bent slightly downwardly towards saidconveyor to insure that substantially all portions of said clips remainsubstantially coplanar with the top surface of said conveyor duringmovement thereof.

12. A filter according to claim 7 wherein the width of said clipsbetween said first and second side edges is less than the width of saidconveyor links. whereby said clips permit free pivotal movement of saidlinks about said transverse bars through a curved path of travel.

13. A filter according to claim 7 wherein said links have a generallyzig-zag configuration including a plurality of integrally formed andoppositely extending generally U-shaped members, with said links beingslightly overlapped with respect to adjacent links whereby the bightportions of said U-shaped members extend between the legs of theU-shaped members of adjacent links, said clips having a width dimensionbetween said first and second side edges which is less than the distancebetween bight portions of successive links, whereby said clips permitfree pivotal movement of said links about said transverse bars through acurved path of travel, while said projecting tongues extend over theiradjacent transverse bars to positions adjacent the edges of an adjacentclip thereby to form said substantially continuous support surface.

[4. A filter comprising a frame, a perforate endless conveyor supportedin said frame to form a pool of liquid supplied to the top thereof,means for moving said conveyor in said frame, a sheet of filteringmedium positioned on and supported by said conveyor for movementtherewith and sealing means having resilient strips extending fromopposite sides of said frame and engaging the sheet of filter mediumadjacent to and inwardly from its opposite side edges to retain theliquid to be filtered in said pool; said conveyor comprising a series oftransverse conveyor bars and a plurality of "zig-zag shaped linksrespectively pivotally connected between adjacent pairs of bars, saidzig-zag" shaped links each extending transversely of the path of travelof the conveyor and being formed of a plurality of generally U-shapedlink sections alternately opening in opposite directions and pivotallyconnected adjacent their bight portions to said transverse bars wherebysaid links are partially overlapped with the bight portions thereofpositioned between leg portions of adjacent links; and a plurality ofremovably mounted clips,members secured to said conveyor in generallylongitudinal alignment with each other for providing a substantiallycontinuous support surface for supporting the portions of said filtermaterial passing under said sealing strips, each of said clip memberscomprising a relatively flat main body portion for covering portions ofan associated link, said main body portion having first and secondopposite edge portions, said first edge portion including a projectionextending outwardly therefrom and a pair of adjacent shoulders onopposite sides of said projection, said projection including a free endportion extending over its adjacent transverse conveyor bar. said secondedge portion having a pair of spaced projections extending outwardlytherefrom and defining a recess therebetween of generally complementaryconfiguration to the projection on said first edge portion; said pair ofprojections having free end portions extending over their adjacenttransverse conveyor bar, said projections on said clip each includingtab means extending downwardly from the free end portions thereof topositions below and beneath their associated projections and locatedadjacent independent bight portions of its associated link for removablysecuring the clip to said adjacent transverse conveyor bars; with theprojection on said one side received in the recess of the other side ofan adjacent clip, thereby to form a substantially continuous supportsurface with adjacent clips.

15. The filter as defined in claim 14 wherein said tabs are formed toengage confronting surfaces of their associated transverse conveyorbars.

16. The filter as defined in claim 15 wherein said tab means each havere-entrant curved surfaces formed thereon with the curved surfaces onthe tabs at opposite side edges of said clips opening in oppositedirections to engage the confronting surfaces of adjacent transverseconveyor bars.

17. The filter as defined in claim 14 wherein said clips are secured tosaid conveyor in predetermined locations with respect to one another,with the projec tions on said one side of said clips being received inthe recesses formed on said second side of adjacent clips, thereby toform a substantially continuous support surface for the filter medium.

18. The filter as defined in claim 14 wherein said clips have apredetermined peripheral configuration selected to cover only portionsof its associated links thereby to permit free pivotal movement of saidlinks about said transverse bars through a curved path of

1. In a filter of the type having a movable perforate conveyorcomprising a series of transverse bars and links interconnecting saidbars, a sheet of filter medium supported on the top surface of saidconveyor for movement therewith, means cooperating with said conveyorand filter medium for forming a pool of liquid to be filtered on saidfilter medium, and means comprising fixed sealing strips on oppositesides of said pool bearing against side edge portions of said filtermedium for inhibiting flow of liquid from the sides of said pool, theimprovement which comprises means operatively connected to saidperforate conveyor for providing a substantially continuous supportsurface for supporting the portions of said filter medium passing undersaid sealing strips, said supporting means comprising a series of clipseach of which has an upper surface substantially coplanar with the topsurface of said conveyor and resilient tab means for removably securingthe clip to the conveyor; said tab means comprising downwardly extendingcurved extensions of said clips resiliently engaging said transversebars of said conveyor; said clips having first and second opposite sideedges of predetermined generally complementary configuration includingprojections having free end portions extending over their adjacenttransverse conveyor bars, thereby to form said substantially continuoussupport surface with adjacent clips; said tab means extending downwardlyfrom the free end portions of said projections to positions below andbeneath the projections for resilient engagement with their associatedtransverse conveyor bars.
 2. A filter according to claim 1 wherein saidclips each include at least two downwardly extending curved extensionslocated in opposite sides of the clip for respective engagement withadjacent bars of said conveyor.
 3. A filter according to claim 2 whereinsaid downwardly extending curved extensions on said clips respectivelyengage confronting surfaces of adjacent bars of said conveyor.
 4. Afilter according to claim 3 wherein said clips are respectively securedto said conveyor between successive pairs of transverse conveyor bars insubstantially longitudinal alignment with each other to form acontinuous row of clips along the conveyor.
 5. A filter according toclaim 4 wherein the curved extensions on adjacent sides of successiveclips in said row of clips engage opposite sides of the same transverseconveyor bar.
 6. A filter according to claim 1 wherein said projectionson said clips comprise a projecting tongue extending from one of saidedges and a pair of spaced projecting tongues extending from the otherof said edges and defining a recess therebetween of generallycomplimentary configuration to the projecting tongue on said one of saidedges; said clips being secured to said conveyor by said tab means withthe tongue on said one edge of each of said clips extending into therecess on the other edge of its associated adjacent clip, thereby toform a substantially continuous support surface.
 7. A filter accordingto claim 6 wherein each of said clips includes at least three of saiddownwardly extending tab means formed thereon, one of said tab meansbeing formed integrally with and depending from the free end of thetongue on said one edge of the clip and the other two of said tab meansbeing formed integrally with and depending from the free ends of theprojecting tongues on the other edge of the clip adjacent said recess,said tab means respectively comprising resilient curved extensions ofthe clips located below and beneath their associated projecting tonguesfor resiliently engaging the bars of said conveyor.
 8. A filter asdefined in claim 7 wherein said downwardly extending tab means areformed to resiliently engage confronting surfaces of adjacent transverseconveyor bars.
 9. A filter as defined in claim 8 wherein said tab meanshave re-entrant curved surfaces formed thereon with the curved surfaceson the tabs at opposite side edges of said clips opening in oppositedirections to engage the confronting surfaces of adjacent transverseconveyor bars.
 10. A filter as defined in claim 8 wherein said tabs eachhave an inclined free edge portion defining a cam surface for guidingits associated tab into resilient mating engagement with its associatedtransverse conveyor bar.
 11. A filter as defined in claim 7 wherein saidtongue on said one edge of each of said clips, and said one edgethereof, define shoulder portions in said clips adjacent said one edgethereof, said shoulder portions of said clips being bent slightlydownwardly towards said conveyor to insure that substantially allportions of said clips remain substantially coplanar with the topsurface of said conveyor during movement thereof.
 12. A filter accordingto claim 7 wherein the width of said clips between said first and secondside edges is less than the width of said conveyor links, whereby saidclips permit free pivotal movement of said links about said transversebars through a curved path of travel.
 13. A filter according to claim 7wherein said links have a generally zig-zag configuration including aplurality of integrally formed and oppositely extending generallyU-shaped members, with said links being slightly overlapped with respectto adjacent links whereby the bight portions of said U-shaped membersextend between the legs of the U-shaped members of adjacent links, saidclips having a width dimension between said first and second side edgeswhich is less than the distance between bight portions of successivelinks, whereby said clips permit free pivotal movement of said linksabout said transverse bars through a curved path of travel, while saidprojecting tongues extend over their adjacent transverse bars topositions adjacent the edges of an adjacent clip thereby to form saidsubstantially continuous support surface.
 14. A filter comprising aframe, a perforate endless conveyor supported in said frame to form apool of liquid supplied to the top thereof, means for moving saidconveyor in said frame, a sheet of filtering medium positioned on andsupported by said conveyor for movement therewith and sealing meanshaving resilient strips extending from opposite sides of said frame andengaging the sheet of filter medium adjacent to and inwardly from itsopposite side edges to retain the liquid to be filtered in said pool;said conveyor comprising a series of transverse conveyor bars and aplurality of "zig-zag" shaped links respectively pivotally connectedbetween adjacent pairs of bars, said "zig-zag" shaped links eachextending transversely of the path of travel of the conveyor and beingformed of a plurality of generally U-shaped link sections alternatelyopening in opposite directions and pivotally connected adjacent theirbight portions to said transverse bars whereby said links are partiallyoverlapped with the bight portions thereof positioned between legportions of adjacent links; and a plurality of removably mounted clipsmembers secured to said conveyor in generally longitudinal alignmentwith each other for providing a substantially continuous support surfacefor supporting the portions of said filter material passing under saidsealing strips, each of said clip members comprising a relatively flatmain body portion for covering portions of an associated link, said mainbody portion having first and second opposite edge portions, said firstedge portion including a projection extending outwardly therefrom and apair of adjacent shoulders on opposite sides of said projection, saidprojection including a free end portion extending over its adjacenttransverse conveyor bar, said second edge portion having a pair ofspaced projections extending outwardly therefrom and defining a recesstherebetween of generally complementary configuration to the projectionon said first edge portion; said pair of projections having free endportions extending over their adjacent transverse conveyor bar, saidprojections on said clip each including tab means extending downwardlyfrom the free end portions thereof to positions below and beneath theirassociated projections and located adjacent independent bight portionsof its associated link for removably securing the clip to said adjacenttransverse conveyor bars; with the projection on said one side receivedin the recess of the other side of an adjacent clip, thereby to form asubstantially continuous support surface with adjacent clips.
 15. Thefilter as defined in claim 14 wherein said tabs are formed to engageconfronting surfaces of their associated transverse conveyor bars. 16.The filter as defined in claim 15 wherein said tab means each havere-entrant curved surfaces formed thereon with the curved surfaces onthe tabs at opposite side edges of said clips opening in oppositedirections to engage the confronting surfaces of adjacent transverseconveyor bars.
 17. The filter as defined in claim 14 wherein said clipsare secured to said conveyor in predetermined locations with respect toone another, with the projections on said one side of said clips beingreceived in the recesses formed on said second side of adjacent clips,thereby to form a substantially continuous support surface for thefilter medium.
 18. The filter as defined in claim 14 wherein said clipshave a predetermined peripheral configuration selected to cover onlyportions of its associated links thereby to permit free pivotal movementof said links about said transverse bars through a curved path oftravel.